Yes if the company is no longer in business that the warrenty is through then it can not be honorred. You could buy a third party warranty.
No, not every GMC SUV comes with a 5 year warranty. The most common warranty is for 3 years. The GMC site has a list of all SUVS and you can check for each individual warranty.
The drivetrain warranty of the 2009 GMC Yukon is 5 yr./ 100000 mi.
The drivetrain warranty of the 2005 GMC Yukon is 3 yr./ 36000 mi..
The 2003 GMC Yukon has a 3 yr./ 36000 mi. basic warranty.
The drivetrain warranty of the 2010 GMC Savana is 5 yr./ 100000 mi..
The 2014 GMC Savana has a 3 yr./ 36000 mi. basic warranty.
The drivetrain warranty of the 2015 GMC Yukon is 5 yr./ 100000 mi..
The 2015 GMC Yukon has a 3 yr./ 36000 mi. basic warranty.
The 2007 GMC Yukon has a 3 yr./ 36000 mi. basic warranty.
The 2001 GMC Savana has a 3 yr./ 36000 mi. basic warranty.
The drivetrain warranty of the 2007 GMC Savana is 5 yr./ 100000 mi..
The drivetrain warranty of the 2008 GMC Savana is 5 yr./ 100000 mi..